Water Stewardship Information Sources

Citation Hocking, MD et al. 2013. Ecosystem based management in the Great Bear Rainforest: A knowledge summary for priority ecological questions and experimental watershed design. Prepared for Coast Forest Region, FLNRO.
Organization SFU
URL https://morganhocking.files.wordpress.com/2013/10/hocking-et-al-2013_ebm-in-the-gbr_priority-questions-and-experimental-watershed-design.pdf
Abstract/Description or Keywords In response to concerns that conventional forest management results in biodiversity
loss and limits social and economic opportunities for future generations, Ecosystembased
Management (EBM) has been adopted within the Central and North Coast area of
British Columbia (Price et al. 2009). The Land Use Objectives (LUOs) were developed
to support implementation of EBM (Central and North Coast Order 2009) and it is
expected that they will be reviewed and amended if they do not perform well in terms
of improving ecological and human well-being. Adaptive management will guide
research and monitoring to examine how well these management goals are being met.
The Experimental Watershed Programme was established to conduct large-scale
research and monitoring initiatives that examine the outcomes of forest management
practices under EBM. To inform the design of this Programme, the Coast Area Forest
Research Team of the Ministry of Forests, Lands and Natural Resource Operations
(MFLNRO) compiled a list of priority research questions related to uncertainty around
how forest management impacts physical and biological components of forest
function, and around the efficacy of critical definitions within the LUOs.
The four priority research questions are as follows:
• Priority Question 1 - Hydrological Issues associated with definitions of function
and relationship to management.
• Priority Question 2 - Information on buffers (management implications,
characteristics of streams that interact with and affect role and application of
buffer management).
• Priority Question 3: Issues of range of natural variation in amounts of forested
systems, habitat supply thresholds, and landscape-level conservation.
• Priority Question 4: Interactions between stand-level retention and landscapelevel
representation/conservation. Responses to these questions will update the existing body of knowledge available to
MFLNRO on these issues (e.g. as discussed in Fenger et al. 2009), and are anticipated
to help guide experimental work as well as inform revision of the LUOs. Therefore,
there are three primary objectives of this report:
1) To synthesize primary and grey literature published from 2002 to present
pertaining to the priority forest management research questions;
2) To review the efficacy of the BC EBM LUOs and make recommendations for
their revision based on primary literature; and
3) To identify knowledge gaps in the literature that could be investigated using an
experimental watershed approach and suggest methods to be incorporated in
the design, implementation, and data analysis of experimental watershed
projects.
Main Findings
Priority Question 1:
• The terms 'functional' in functional riparian forest and ‘hydrologically effective
greenup’ as defined by the Orders should be clarified.
• Equivalent Clearcut Areas (ECA) of 20% in coastal watersheds may still pose
significant risks to stream structure and function.
• Headwater streams should be afforded increased levels of protection to
minimize forestry-related risks to hydrologic function.
• Forest harvesting impacts to hydrologic function are predicted to vary
considerably across the diverse environmental gradients present in the Great
Bear Rainforest. The ECA framework would thus benefit by including the
diverse factors that affect stream flow such as climate, vegetation, elevation,
topography, soil types, presence of lakes, glaciers, etc.
Priority Question 2:
• At the landscape scale, connectivity of channels to uplands, headwaters to
ridgelines, and linkage areas should be maintained.
• 1.5 times tree height is not likely to be effective in maintaining the diversity of
riparian reserve functions if the dominant trees are 20 m or less in height.
• TSFA stability ratings are unlikely to appropriately identify downslope areas
that are at risk of upslope landslide activity. • Requiring riparian reserve zones only for S1 to S3 streams is not sufficient to
protect these streams from negative impacts of upstream harvesting.
Increasing riparian buffer width for S4 to S6 streams (fish-bearing or not), will
reduce downstream impacts of forest harvesting.
• The foundation for determining riparian practices is largely fish-based, yet
there is no scientifically-sound basis for managing riparian and aquatic values
on the presence of game fish alone. Research continues to support that
monitoring stream-associated amphibian populations provides a better index of
riparian forest functioning and biodiversity.
Priority Question 3:
• Species loss and population declines will take place above threshold levels.
• Critical habitat for priority species has in most cases been identified and in
some cases mapped.
• Fungi, lichens, bryophytes are among the most sensitive to logging. Monitoring
these taxonomic groups is likely to provide sensitive tests of the impacts of the
spatial arrangement of logging at both stand and landscape scales.
• Habitat quality is a key predictor of species distributions; therefore, not
accounting for it in studies of species responses to habitat loss and
configuration may lead to inaccurate conclusions.
Priority Question 4:
• The literature agrees that most species, especially late-seral species, decrease
in abundance and richness with less than 15% retention.
• The literature appears to support definitions of high risk at the stand scale as
15% retention, and low risk as retention that exceeds 70%. Kremsater et al.
(2008) would recommend a minimum of 30% retention.
• Landscape-level studies of habitat representation are lacking.
Implications for Experimental Watershed Design
Although there has been a substantial amount of research on topics relevant to the
priority ecological questions in the past few years, there remain major gaps in our
understanding. Most uncertainties stem from the fact that there are currently very
few studies at the landscape scale. The Experimental Watersheds Programme has the
potential to fill significant knowledge gaps in our understanding of ecosystems at the
landscape level. For example, with BC’s BEC classification system, a unique
opportunity exists to link studies to BEC Site Series in order to measure landscapescale
representation. Throughout this report, we list considerations for Experimental Watershed design
(EWD) that have been informed by recent literature. We recommend the design of the
Programme to include:
• A minimum of 50 S1 to S3 streams and 100 to 1000 S4 to S6 streams, with
differences in the intensity and frequency of surveys depending on stream
type.
• A partnership with the Central Coast First Nations in monitoring priority
watersheds on the Central Coast should be implemented.
• A partnership with academia (e.g. the Hakai Network) as well as among other
stakeholders (DFO, MoE, forest companies, Hakai Institute).
• Greater than 10 years of data collection to account for delayed responses.
• Investigation into the short- and long-term response of headwater ecosystems
to disturbances.
• Linking changes in species responses to measures of landscape disturbance,
rather than just amount of forest cover, to provide a more relevant measure of
risk.
• Assessments of population density, distribution and habitat relationships for
both priority and non-priority species (e.g., brown creeper, northern flying
squirrel) that are sensitive to harvesting.
• An assessment to understand the state of knowledge and level of uncertainty
associated with the range of natural variability in each BEC zone.
• Use of late seral-associated forest species as indicators of retention
effectiveness
• Economic analyses that evaluate tradeoffs between different forest practices,
including the possibilities surrounding carbon credits, more community-based
processing of wood products, and tourism.
Information Type report
Regional Watershed Central Coast
Sub-watershed if known
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Project status complete
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